1. Field of the Invention
The present invention is in field of the packaging technology and concerns a method and a device according to the generic terms of the corresponding independent claims. The method and the device serve for strapping substantially parallelepipedic objects or stacks of objects, the objects or stacks being conveyed into a strapping position, being stopped there and strapped and then being conveyed out of the strapping position.
2. Description of the Prior Art
It is known to strap, in a strapping position, substantially parallelepipedic objects or stacks perpendicular to the conveying direction by positioning a loop of tape drawn from a storage reel in a tape channel arranged in the form of a loop around the conveying path, by pulling the tape out of the channel and thus placing it around the object and by tensioning and closing the tape loop and by cutting the tape loop off the tape on the storage reel. The strapped object is then conveyed out of the strapping position.
Devices with tape channels for carrying out the transverse strapping as briefly described above are e.g. described in the publications U.S. Pat. No. 4,520,720 or DE-3814029. Such devices are used in many applications and the strapping produced meets the required standards.
One disadvantage of the known devices for transverse strapping is the fact that they are complicated and require a large number of movable components. The tape channel must be closed over its whole length for introducing the tape loop and must be opened for extracting the tape loop and is therefore a very complex device component. If, in addition, the device is to be used with a strapping material having a stiffness insufficient to be pushed into the tape channel the tape channel, becomes even more complex.
A further disadvantage of the known devices with a tape channel is the fact that the strapping process is not adaptable to different formats of objects to be strapped. The tape loop to be prepared for each strapping cycle is of the same size independent of the format of the object to be strapped. This means that when strapping smaller objects a longer length of tape must be pulled back which increases the cycle time.